Throughout Endeavor, black boxes warmed to life. Navigation beacons prepared to steer Shuttle back to an emergency landing at Cape Canaveral’s concrete, three-mile-long runway if a launch malfunction during the first 265 seconds of powered flight dictated a high-speed turnaround for a perilous Return To Launch Site abort, or RTLS. In the mission simulator, Parker and Enright had bent their metal and had gotten their feet wet more than once.
“Copy, Flight. Configured for RTLS steering… Let’s hope not,” the AC sighed.
“Endeavor: At T-20 minutes, configure GPC to ascent OPS-1”
“This is the AC. We’re running computer Operations Sequence One outbound. Cabin vents comin’ closed now.”
“Roger, Aircraft Commander.”
Endeavor’s four primary General Purpose Computers concentrated on the OPS-1 launch program for steering the powered launch phase. In the fifth back-up GPC, a separate ascent program ticked away, ready to fly Shuttle aloft if computers One through Four should fail. Trajectory graphs blinked upon the front instrument panel’s three television screens on the flightdeck.
“Endeavor: You’re Go at T-19 minutes and counting. Configure computer Error Logic to RESET position, and configure GPC to MM-101 and OPS-9.”
“Copy, Flight,” the AC called. “Major Mode 101 is running.” With Operations Sequence Nine, the on-board Shuttle computers were taking Endeavor’s pulse as her own black boxes monitored the computerized, pre-launch checkout. Shuttle is America’s first manned spacecraft designed to automatically launch itself with its own, onboard computers.
“Endeavor: You’re Go at fifteen minutes and counting. We’re now conducting the nitrogen purge of the SRB skirts. Configure OMS and RCS crossfeed valves for launch.”
“Okay, Flight,” Parker replied lazily. The command pilot was relaxed and ready to fly. With his legs elevated above his reclining body, the throbbing in his right leg ceased and he was comfortable.
“Okay, Number One. Panel Overhead Seven: Left, aft RCS pod, crossfeed lines One and Two configured GPC talk-back closed, and crossfeed lines Three, Four, and Five, configured GPC talk-back closed. Right, aft RCS crossover lines One and Two to GPC talk-back closed. Lines right Three, Four, and Five, to GPC talk-back closed. And, master RCS crossfeed locked off.”
“Okay, Flight. Our RCS crossfeed is ready to go.”
“Copy that, right seat. We’re listening.”
“Ready for OMS, Skipper.”
“With you, Jack. Panel Overhead Eight: Left OMS crossfeed Loop A and Loop B to GPC talk-back closed. Left OMS engine, lever-locked armed, Panel Center Three. OMS right: Crossfeed Loops A and B to GPC talk-back closed. Right engine lever-locked armed, Panel Center Three… OMS primed and ready, Flight.”
“We copy, Endeavor. At ten minutes and counting, we see cabin vents are sealed.”
“Roger, Flight. Vents closed.”
Fifteen hundred miles to the north, an exhausted Admiral nodded his sagging face. A Colonel at his side spoke into a red telephone in a glass room where no sun ever shines. The haggard Colonel laid the phone down gently and he wiped his hands upon his thighs as if the instrument were unclean.
“Endeavor: You are Go at T-9 minutes. Start your event timers at this time. The Ground Launch Sequencer now has the con.”
“We see it here, Flight.”
The countdown was now fully automatic. The master launch computer could either let the count go to zero or could stop the countdown at any moment.
“And, Endeavor, we are now feeding you the new PTI-7 routine for re-entry.”
The two pilots flat on their backs glanced sideways at each other. Five on-board computers swallowed the Programmed Test Input Number Seven to be engaged during re-entry.
“Alright, Flight,” the Colonel shrugged high atop Pad 39-A. “We see lox tank in the ET topping off now.”
Inside the silo-size external tank bolted to Endeavor’s belly, the liquid oxygen, or LOX, tank had been continuously venting out frigid vapors into the clear morning air. As the super-cold gas vaporized, the ET’s supply of 140,000 gallons of liquid oxygen was steadily replenished through lines running from the launch tower. Now the replenishing and venting of oxygen stopped so the sealed tank could build up flight pressure.
Twenty-seven hundred miles away, over California, the killer satellite LACE crossed the American coastline at its ground speed of 300 miles per minute. The silent, slowly tumbling bird whirled eastward toward Florida. LACE would soar directly over Cape Canaveral at the instant Shuttle rode the fire into the sky.
“At seven minutes and counting, Endeavor, the access arm is in motion. You’re on your own, guys.”
Outside, the catwalk from Pad 39-A jerked away from Endeavor’s closed side hatch. The long arm would require one minute to swing back to its locked position next to the tall gantry well clear of Shuttle.
As the crew access arm left Shuttle’s glass side, Endeavor at last stood naked and white in the dazzling daylight. Portions of her round nose and the forward parts of the two OMS pods showed slightly dark scorch marks from her past re-entries from orbit.
Along Cocoa Beach and the Kennedy Space Center’s Merritt Island sands a thousand eyes squinted into the sun as hearts beat faster in time to the two hearts strapped within Endeavor’s aluminum soul.
“Endeavor: At six and counting, confirm faceplate visors closed and locked. Configure APU for startup.”
“Roger, Flight,” the command pilot called as he and Enright pulled their clear faceplates down over their faces. As each pilot locked his faceplate into position on his helmet, the pilots’ nostrils inhaled the spaceman’s blend of bottled air laced with the smell of rubber hoses and sweat.
“Ready for APU checklist, Will,” Enright called through the flightdeck intercom. His voice was anxious.
When the three auxiliary power units were lit to supply pressurized hydraulic fluid to Shuttle’s wings and tail and to the steering motors which swing the three space shuttle main engines, the ship would be committed to fly within five minutes. Failure to go would mean shutting down the APU’s and returning to the T-20 minute point in the countdown to give the APU’s time to cool. Enright was tense. Like a pilot’s first solo flight from a long-ago grass field, like a body’s first wet kiss, to practice for a lifetime cannot dilute the gut’s tension at the event. Enright raised his right gloved hand to the instrument panel above his right elbow. He had done so a thousand times before, in the mission simulator and in his sleep. But this was the first time he did it with his hands sweating.
As his captain recited the checklist for the APU’s, Enright’s right hand waited for each command before his fingers threw the silver toggle switches.
“Okay, Number One, this one’s a keeper. On Panel Right-Two: APU Numbers One, Two, and Three, controller power lever-locked on.”
Enright flipped three switches.
“Fuel tank valves One, Two, and Three lever-locked open.”
“And, APU’s One, Two and Three barber-poled as ready, Skipper.”
“Okay, Jack. Speed select to normal One, Two and Three.”
“Speed normal, all three APU’s, Will.”
“All hydraulic main pump pressures to normal.”
“Normal, normal and normal, Skipper.”
“And, automatic shutdown to enable, Jack.”
“Enable.”
“Fuel pump valve coolant, Loops A and B, to auto.”
“Auto, auto and auto.” Enright returned his clammy hand to his lap.
“Endeavor: At five minutes and counting, your flight recorders are running. You’re cleared to crank up the APU’s.”
“Rogo, Flight,” Enright called. “Number One, lever-locked start! Number Two, start! Number Three, lever-locked start! And, we have APU ignition times three. Hydraulic pressure is up and in the green. Three water spray boilers also on-line and green all values. Hydraulic fluid at 220 degrees with APU lube oil at 270 degrees.”